Piston ring grinder



Oct. 2, 1945. R. F. FLORA 2,385,97-9

- PISTON RING GRINDER Filed Sept. 16, 1942 2 Sheets-Sheet l .02 I RudolphRHora Pmorneg R. F. FLORA PISTON RING GRINDER Oct. 2, 1945,

Filed Sept. 16, 1942 2 Shee tsSheet 2 w a m m 1 Q1, Mn w I F h U0 mu (2 .m u A 8 w Z!' Q 747 l 0 m 2 4 V s. we

Patented Oct. '2, 1945 UNITED rsTATes The fllover Foundry Company Mm Mich.,acorporation of t v Application September 16, 1942, sens-1 No. 458, 48.2 M Q ufacture jpiston rings from individual ring cast- 6 ings, finishing each casting to provide a .completed piston ring, though in some cases .ring castings are produced to make two and at times three finished rings from onecasting. Generally such ring castings are of an out-of-round Iorm, 10

being cast from patterns which were initially circular in form then split at one side and a segment inserted in the gap, .A portion of the ring castin vpliodueed from such pattern is removed to correspond with said segment insert, whereby when the piston ring finished it normally is open .a distance at the gap which, upon being closed, causes the ring to take a circular-form and produces an inherent tension in the ring causing it to press outwardly against a cylinder wall. Other rings, known as dead rings, may be made from patternsof substantial circular form so that the castings are nearly if not truly circular.

In all of suchcasting of .ring castings, whether 21$ "for individual rings, or two or more of the Tings from .a single casting and whether in an out-ofround or circular form, the metal flowing into the mold recessesreaches said recess through gates extending outward from a central snrue into which the molten metal is poured. When the molding sand is shaken loose from thecom- 'pleted castings there is a treeof'castingshav- "ing a central trunk produced by the molten metal w remaining in the sprue and branches from the trunk ending in ring castings which are connected with the tree by the molten metal which has filled and solidified in the gates. The ring castings are broken from the tree easily and read- H ily butf'leaving rough projections where .such con- .nections between castings and central tree are broken. Also .in the castings of rings af-hard and tough outside skin is produced around the castings where the molten metal contacts the sides of the recess of the sand mold making a reiatively "rough surface and one which has to The initially removed .before finishing the rings. (Of course all mold recesses are not perfect and there may be and frequently are projections extending g from the ring castings because of minorfiefects (i0 in the molds.

"The first operation generally performed a ring casting is to rough or snag'gr'ind In early practice this was done :by hand operation, "workmen-picking'up'tlre castings singly and'bring- "5 ing them against the sci-m ee or; rapidly rotat- 1mg fin hee lvremevee e pe fi 9f the gatevproiiections which were left and as much of the onter snrface qffthe ring lcasting as seemed necessaryQ This; individual grinding; by hand has iongl since been superseded by quantity production machines, Ihe qresent invention is directed to ain chine for roujghor snag grinding the outer curved surface r sing casting and ch i a l fe tfine e tinss Dir-M1 11 s e? without changing the setup of the dnachine to an ia e n wh ch, w l at w elie t ng l jo iw fr iipd fleetsed se h i u u ll ie castings ca ti om "which we vv "si g fi st? be mad v 'Obieets and purpo'sesofflthe presentlinventign are o'rr e 1 anners-we n ro or sna 1 "w n of Pi n. a ti l ilfi d ere a mfil e wi h T efiee QW t P ov d ncreased production whereing nding whee'1sniay ofythe ring, castings 'Inaintained straight and normal to the sides thereof. l

With invention. .also, the grindingfwheels may be n er fi s dfi ho lti Q ume in changing. the setup 'when g rinding ispresumed; the grinding wheel may fhe quickly changed with no :lje seftup required upon resumptibn o sr di san wi hzmmfemom o one the rings in grinding position and to remove them after grinding with correspondingly less danger to an operator of .themachine. These and other obje s rim inv n i no a t s me sp lcifically stated will be apparent upon an understanding of the invention frorn the following descriptiomftaken in connection with the accomne wi ss injwhi hz a v Fig. 1 is a front elevation of. a grinding machine "made in accordance ,with my invention.

'Fig. "2 is an elevation ioo'liing at the machine from thefilefft in Fig.1.

e. 3 i e I -eme i rn iev mfi 0f thelup r hereof efmw ne w th s me r m e sm s icons-g at the machine from the right in Figsi,

of the. Wheel and said ring castings take the wheel 3 is secured, the shaft being power driven 5 in any suitable manner at high speed;-in;-the operation of the machine. A cylindricalmeinber 4 is permanently connected integrally-or 'other Wise with the casting I below the grindingwheel,' on which a bracket 5 is mounted by means of a split collar 6 tightenedupon the member.;;- a; by set screws at a desired position, I The bracket 5 at its upper side is provided with spaced apart upwardly extending lugs .1 upon which a ring arbor carrying support 8 is tiltably mounted by means of ashaft 9 as shown, whereby said support 8 may be tilted aboutthe axis of the shaft 9 toward or away from the outer .flat side of the grinding wheel. a The support 8 at one side has an upwardly extending arm [is terminating in a journal II while at the. other side it is provided with an. upwardly extending arm to the upper end-of which a gate I 3-is pivotallymounted by apivotpin M as bestshown inFig.1. An arbor is mountedin thejournal ll including-a shaft section I 5 rotatably mounted in said journal from which an arbor 16 extends to lie parallel to the outerface of the grinding. wheel. The arbor is of smaller diameter than the shaft section l5 thereby providing a. continuous .annular-shoulder l1 between. the arbor-and the adjacent endv of the shaft. .The outer end ,of the arbor is provided with ahead, as indicated at l8,.larger in diameter thanthearbor l6 where it connects with'the arbor forming a second con.- tinuous annular shoulder adjacent the outerend of the arbor. At the endofthe. journal H.-.a plate 19 is permanently secured of the form best shownin Fig. 5. A plurality of the ring cast.-

, ings 20 are placed over the. arbor by moving the .gate l3 tothe dotted line position shownin Fig. 1, then returning the gate to its operative position, said gate having an opening for the-reception of the head .l8 (Fig. 4).'

At the outer end of the arbor shaft a pulley 2| is secured, driven by an endless belt 22 which also passes around a. pulley 23 which is con- 55 'nected with a second pulley 24 torotate therewith both about the axis of the shaft, 9. The pulley 24 is driven by an endless belt 25. Which passes arounda pulley ZGsecured tofthe shaft of an electric motorv 21 mounted on a suitable bracket 21a extending from thesupportingcastmg I. i f When the motor is operating the arbor i6 is driven with that portionof its periphery adjacent the grinding wheel 3 traveling. in the same direction but at considerably less speed. The location of the arbor is above the horizontaldiameter of the grinding wheel .3 with the axis of said arbor substantially parallel to the horizontal. Such positionof the 1 arbor may be changed by adjustment of the bracket 5 about the member 4. When the arbor carrying: support 8 is moved toward the grinding wheel the ring castings are brought against the outer side face position shown in Fig. 5, pressing against the outer side of the grinding wheel and against the arbor with the end ring casting nearest the plate l9 coming against the shoulder I i. With the rotation of the grinding wheel in the direction of the arrow in Fig. 1, the tendency is to move the castings to the right (Fig. 1) so as to hold. the end casting always against said saouraer lfl f iflfhe ring jcastings' being disposed above the horiz'ontal diameter of the grinding 7 wheel, the action of the wheel upon the outer ciirved surface of the ring castings is what ma :beterrned-a diagonal movement across from one side to the other of the ring castings. Simulxtaneously the 'ring castings are rotated by the rotationof'the arbor coupled with their pressure against the grinding wheel 'l hemovementwof. the arbor toward the grinding wheel is controlled by an adjustabl mounted pneumatic mechanism shown in Fig. 3. A guide 2.8...is secured .to a side of the. main casting l uponfwhich a b1ock 23 is slidably mounted and adjusted by means of a hand operated. screw as shown in Fig.3. .Atone endthe block 28 is provided with an. upwardly extending arm. An'air cylinder 3| at one endhas a projecting fork 32. pivotally connected by means of a pivot pin. 33 to'the upper portion of said arm, A piston 34} within the. cylinder hasa piston rod 35 connected therewith which passes through one end of'ithe'. ,cylinder and has, a pivotal connection with a lug 36 extendingfrom the arbor supportingm'ember 8, substantiall midway between itfsiupperjand lower ends Compressed air is carried into thecylinderthrougha conduit 3! toftransmititsiorce against said piston to move it and move the arboritoward the grinding wheel.

Thejloperationfof the motor 2? is. controlled .byan automatic. mercury switch 38'mounted at asidej of the arbor support 8 with the usual cable 39 [carrying the. circuit wires from said switch tQlthe motor and source of electric power. On1the.;til ting of the, arbor carrying'support to its operative position, shown in Figs. 2 and 3, the mercury. switch isautomatically closed thus .ener'gizingthemotor 21 for operation. On moving the arbor fandsits support away. from the "wheel to thedott'ed line position shown in Fig. 2,

,said switch is automatically disconnected and the motor stops. The outward movement to said dotted line flposition is controlled as to its extent by stop lug's 40 at the lowerpart of the arbor carrying support. 8; which. comes .against the bracketyS when. apredetermined outer position a is reached. It is in this position with the arbor at rest and motor ZTnot operating that the arbor jis jloaded with ringlcastings for processing and the processedfc'astings removed from the arbor after they have been ground.

In' thei operatiomwith the motor 21 at rest the arbor and its. support are at the dotted'line position shown in Fig. 2 the gate [3 is turned about the pin M. to the dotted line position shown in Fig.1, the desired number of ring castings placed on the arbor-and thegate turned to its upper position: The gatemay be provided with a yielding spring which will normally hold it in operative position- Compressed air is then directed in- .toithe conduit 31. by means of .a suitable valve control, moving the piston 34 to the right (Fig.

aesaev'e tinuously at high speed. The "control of the amount of grinding at the outer curved surface or the rings is through the adjustment effected; by the adjusting screw 38,. L The outward movement of the arbor and its supportto the dotted iineposition shown in Fig. 2 is performed manualiy, opening the control valve for the-compressed air to exhaust the air in the cylinder at an'dpermit such outward movement a simultaneous movement or the piston 3f4 i:o'the left rig. 3 In this position the gate 1'3 isfturned to per'rhitthe removal ofth'e processed rings and their replace ment by another quantity orjring ea t'ings to be processed.

With this eons'truei'ien of grinding machine,

ring castings of many different sizes and diameters may be rough or snag ground at their outer curved surfaces without substantial change in setup of the machine, at least no more than the adjustment change required for a different radial thickness of ring castings which will be taken care of by the hand operation of adjusting screw 30.

The operation is relatively simple and production of rough ground rings is rapid. The diagonal grind across the peripheries of the rings maintains the outer curved surface of the ring normal to the sides thereof without rounding or concaving of the ring surface. When required the grinding wheel may be quickly dressed without change in the machine setup. The grinding wheel may be used almost completely. It is evident also that by simple modification two grinding wheels one at each end of the shaft 2 may be supplied each with an arbor mechanism, or other alterations of an equivalent nature made to provide two grinders on one base or supporting structure. Ring castings of a wide range of diameters may be used without variation of the ring set up. The diagonal grinding also tends to hold the rings on the arbor at the same positions with the ends ring bearing against the stop provided by the shoulder at H. The control of the pressure of the ring castings against the grinding wheel is accomplished through manual control of passage of compressed air into the cylinder which may be controlled as to quantity, may be shut off or very nearly shut off and otherwise readily controlled for the best results whereby heat generated while grinding is at a minimum and the grinding pressure controlled thereby avoiding ring breakage.

The mechanism described as an embodiment of the invention may be altered in specific detail. For example, while the adjusting screw 30 for the block 29 and the end of the piston rod 35 coming against the end of the cylinder 3| effects a stop for the grinding of the castings, such stop is not absolutely necessary as the control of rough grinding is obtained readily by controlling the compressed air flow to the cylinder by manual operation of the air control valve. The valve may be of a threeway character likewise and air alengagement of gate projections or other projections against the grinding wheel.

, This machine has been produced and is used regularly in rough and snag grinding of piston rings and has proved exceptionally serviceable in all respects.

1 The inventionis deiihedin the appended claims and is to beeorrsidered comprehensive of an forms of structure coming within their scope.

-=ri=claim z i i "1'. In a grinding 'imachine, a driven grinding wheel, a rotatably mounted arbor over which a piuralityof ring castings are placed, said arbor beingoi less 'diameterthan the interiordiameter or themes-tings, said arbor having a free end and a shoulder between" its ends against which the first ring casting placed on the arbor is adapted to engage,' a "movably mounted member on which.

said arbor is rotatabiy mounted; means for movin saidmeniber and arbor toward a side or the grinding Wheel to bring the ring castings into grinding enga'gementwith the side thereof the axis of the arbor substantially paralleling a diameter of the grinding wheel and spaced a distance from said diameter and means for causing said arbor to be positively and continuously driven on movement of the arbor and castings to such position, in the same direction as the grinding wheel but at less speed.

2. In a grinding machine, a driven grinding wheel located with its sides in substantially vertical planes, a rotatably mounted arbor, a movably mounted member on which said arbor is mounted, the arbor having a free end portion extending to one side of said member over which ring castings are adapted to be freely placed, said arbor between its ends having a continuous annular shoulder against which the first ring casting placed over the arbor engages, a portion thereof being engaged by a portion of the adjacent edge of the ring casting, means for driving said arbor,

means for moving said arbor carrying member toward a vertical side of the grinding wheel after ring castings have been placed thereon and means for effecting a continuous driving of said arbor at less speed and in the same direction as the grinding wheel when said member is thus moved toward the grinding wheel and for stopping said driving of the arbor when moving away from the wheel, said arbor being spaced a distance from the plane of the horizontal diameter of said wheel. 3. In a machine of the class described, a driven grinding wheel having a vertical grinding face, an arbor carrying member mounted to be moved toward or away from the face of the grindin wheel, a shaft rotatably mounted on said member having an arbor at one end thereof over which ring castings are adapted to be located when said member is away from the grinding wheel, an electric motor, means for driving said shaft from said motor, means for starting said motor upon movement of the arbor carrying member toward the grinding wheel and for stopping operation of said motor on movement of said member away from the grinding wheel, said arbor being of less diameter than the shaft providing a shoulder at their juncture against which the innermost ring casting of the castings placed over the arbor engages at its inner side and said arbor being located in a position above the horizontal diameter of said grinding wheel whereby on engagement of the grinding wheel and rotation thereof in a direction toward the upper portions of said ring castings on the arbor, said castings are moved in a direction to force the innermost casting against said shoulder.- V 4. In a grindin machine, a driven grinding wheel mounted to turn about a horizontal axis and having a vertical grinding face, a movably mounted support located at one side of the face of said grinding wheel and movable toward or away from-it said support havingza journal thereon,-a shaft rotatably; mounted in said journal, said shaft having. an end arbor portion of lesser diameter than the diameter of the shaftproviding an arbor over which a plurality of piston rings may the freely placed, there being a continuous shaft being located to a side to the axis of rotation of the diameter of the grindingwheel and in parallelism to the diameterIof the grinding wheel.

5 A construction,having the elements in combination defined in claim 4, said movably mounted support for said arbor shaft being located with respect to the grinding wheelso that theujo urnal is substantially outside of the periphery of the grinding wheel, and a gate movably mounted on said support adaptedto be moved intoa position in substantial parallelism to the last. ring casting placed over said arbor portion of the shaft but out of contact engagementtherewith or to be moved to a second position away therefrom. n 1

. 7 RUDOLPH F. F'LQRA. 

